A new look at acid catalyzed deacetylation of carbohydrates: A regioselective synthesis and reactivity of 2-O-acetyl aryl glycopyranosides

Nagornaya, Marina O.; Filimonov, Victor D.; Valiev, Rashid R.; Belyanin, Maxim L.; Drozdova, Anna K.; Cherepanov, Victor N.; Stepanova, Elena V.

A new look at acid catalyzed deacetylation of carbohydrates: A regioselective synthesis and reactivity of 2-O-acetyl aryl glycopyranosides

Nagornaya, Marina O., Filimonov, Victor D., Valiev, Rashid R., Belyanin, Maxim L., Drozdova, Anna K., Cherepanov, Victor N., Stepanova, Elena V.

Дата публикации: 2018

Дата публикации в реестре: 2020-12-02T09:54:26Z

Аннотация:

In the present work we report that acetyl groups of per - acetylated aryl glycosides have different reactivity during the acidic deacetylation using HCl/EtOH in CHCl3, which leads to preferential deacetylation at O-3, O-4 and O-6. Thereby, the one-step preparation of 2-O-acetyl aryl glycosides with simple aglycon was accomplished for the first time. It was proved that the found reagent is to be general and unique for the preparation of series of 2-О-acetyl aryl glycosides. We have determined the influence of both carbohydrate moiety and the aglycon on the selectivity of deacetylation reaction by kinetic experiments. Using DFT/B3LYP/6-31G(d,p) and semi-empirical АМ1 methods we have found that the highest activation barrier is for 2-О-acetyl group. This completely explains the least reactivity of 2-О-acetyl group.

Ключевые слова:
арилгликозиды, региоселективное деацетилирование, реакционная способность, частично ацилированные углеводы, моделирование переходных состояний

Тип: статьи в журналах

Источник: Carbohydrate research. 2018. Vol. 458/459. P. 60-66